import java.util.Scanner;
public class SquareRoots {
    public static void main(String[] args){
        Scanner scanner=new Scanner(System.in);
        for(;;) {
            System.out.print("donnez un nombre positif :");
            double x=scanner.nextDouble();
            if(x<0) System.out.println("svp positif");
            else if (x==0) break;
            else System.out.printf("sa racine carree est : %f\n",Math.sqrt(x));
        }
    }
}
